• 연구논문집
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• 통권28호
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• pp.39-47
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• 1998

Industrial electrostatic precipitation is a very complex process, which involves multiple-way interaction between the electric field, the fluid flow, and the particulate motion. This paper describes a strongly coupled calculation procedure for the rigorous computation of particle dynamics during electrostatic precipitation. The turbulent gas flow and the particle motion under electrostatic forces are calculated by using the commercial computational fluid dynamics (CFD) package FLUENT linked to a finite-volume solver for the electric field and ion charge. Particle charge is determined from both local electrical conditions and the cell residence time which the particle has experienced through its path. Particle charge density and the particle velocity are averaged in a control volume to use Lagrangian information of the particle motion in calculating the gas and electric fields. The turbulent particulate transport and the effects of particulate space charge on the electrical current flow are investigated. The calculated results for poly-dispersed particles are compared with those for mono-dispersed particles, and significant differences are demonstrated.

• 한국항해학회지
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• 제10권2호
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• pp.139-155
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• 1986

In this paper the dynamic effects due to the free water motions in tanks upon the lateral motion of a floating body in regular waves are calculated, in order to obtain the relationship between a motion of a floating body and that of the free water in tanks. Under the assumption that the fluid is ideal and motion amplitudes are small, velocity potential of the fluid in tanks is calculated by the source distribution method and the hydrodynamic forces and moments are calculated by the integration of fluid pressures over the tank surface. Hydrodynamic effects of the fluid on the floating body are expressed in terms of added mass and coupling coefficient obtained from the integration. Computations are carried out for ship with seven wide center tanks and comparisons between the liquid cargo loading case and the rigid cargo loading case are shown.

• 대한조선학회지
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• 제23권4호
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• pp.35-43
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• 1986

Recently, the SWATH concept hull form which is capable of high speed navigation with small oscillatory motions in waves, was developed from the catamaran type hull forms. This paper discribes a method to predict motion responses of a SWATH ship in regular waves using the strip theory. The 2-dimensional hydrodynamic problem was solved using the improved Green integral equation which is free from the irregular frequencies. The effects of viscous drag which is dominant in heave damping of the SWATH ship are taken into account. Further, the effects of the stationary stabilizing fins which is important in high speed performance of the SWATH ship are included in the equation of motions. It seems that the motion responses calculated by the present method show better agreement with experimental results than other existing numerical results.

• 한국해양공학회지
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• 제19권5호
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• pp.78-82
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• 2005

The motion response results of a submerged submarine section in waves are presented. The numerical method is based on Cauchy's integral and 3 degrees-of-freedom motions of submarine sections are calculated in two dimensions, in regular waves. The fully nonlinear free surface and body boundary conditions are applied to the present problem, and the viscous effects on the submarine are modeled by Morison's formulas. The motions of submarine sections in beam sea are directly simulated and the effects of wave frequency, snorkel depth, and bridge are discussed.

• 대한조선학회지
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• 제11권1호
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• pp.1-8
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• 1974

Hydrodynamic forces and moments produced by the swaying oscillation on the free surface were exactly calculated by Ursell-Tasai method for the cylinders with Kim's chine form sections and the sway responses of the cylinders of those chine form sections among the regular beam sea were also calculated. The results of the computation were compared with those of Lewis form sections. It is concluded that the effects of the section form on the added mass, and damping are small, if the section forms had same beam-draft ratio and sectional area coefficient in the case of sway motion. It is also known that the above little effects of section shapes on the basic hydrodynamic forces do not effect on the sway motion responses of cylinderical bodies among the regular beam sea. The sway motion responses of cylinderical bodies are varied linearly with the wave numbers.

• Journal of Applied and Pure Mathematics
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• 제4권1_2호
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• pp.9-26
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• 2022

The purpose of this work is to study the existence and continuous dependence on neutral stochastic partial integrodifferential equations with impulsive effects, perturbed by a fractional Brownian motion with Hurst parameter $H{\in}({\frac{1}{2}},\;1)$. We use the theory of resolvent operators developed in Grimmer [19] to show the existence of mild solutions. Further, we establish a new impulsive-integral inequality to prove the exponential stability of mild solutions in the mean square moment. Finally, an example is presented to illustrate our obtained results.

• 대한통합의학회지
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• 제4권1호
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• pp.1-11
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• 2016

Purpose : The purpose of this study was to exam effects of aroma therapy on the woman with headache in range of motion, results based on Pain and the tiredness index. we applied this study in female patients with headache. tiredness, stress, pain to examine effects of easing off headache, Tiredness. Methods : The study has been conducted with three different groups of "H" University in Gwangyang, the forty-five 20's female university student with headache were randomly assigned to groups each groups did a survey to evaluate their tiredness, VAS, VRS before this study and after there are three groups: 15 people gets a swedish massage by using almond oil(I Group, n= 15), 15 people got a swedish massage by using lavender oil(II Group, n=15) and 15 people got a swedish massage by using lavender oil, smalled at the scent of lavender candle(III Group, n=15). I, II, III Group common characteristics(gender, age, height, weight) were measured by using goniometer to measured flexion extension, left right flexion, left right rotation of cervical range of motion. the measured data were analyzed by using repeated ANOVA. Especially in order to investigate the effect of Aroma therapy by using lavender candle this study is progressed 20 minutes, 3 times per week for a term of 3weeks(total 9). Results : The results of this study were as follows : 1) the VAS and VRS showed significant different result. 2) in the range of motion, cervical extension between Group I and II and left right flexion between Group I and III showed quite motional difference. 3) in the tiredness, there were no significant factors after examination. Conclusion : Therefore, the results of this study demonstration that the effect of Aroma therapy by using lavender candle didn't show prominent effects.

• 산업기술연구
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• 제28권A호
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• pp.155-161
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• 2008

Muscle force prediction in forward dynamic analysis of human motion depends many muscle parameters associated with muscle actuation. This research studies the effects of various parameters of Hill type muscle model using the simple hand raising motion. Motion analysis is carried out using motion capture system, and each muscle force is recorded for comparison with muscle model generated muscle force. Using Hill type muscle model, muscle force for generating the same hand rasing motion was setup adjusting 5 activation parameters. The test showed the importance of activation parameters on the accurate generation of muscle force.

• 한국소음진동공학회논문집
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• 제14권1호
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• pp.64-72
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• 2004

In this paper. we analyse and present electro-mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The motions of the ring are electro-statically derived. sensed and balanced by electrodes. The equations of motion are formulated. The measuring method of angular velocities by force-to-rebalance is presented. The dynamic characteristics of a ring gyroscope are calculated and compared.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.890-895
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• 2005

This paper presents the dynamic analysis of a cantilever beam undertaking impulsive force that undergoes rigid body motion. The transient response of the beam induced by the impulsive force and the rigid body motion is calculated based on hybrid deformation variable modeling method by applying the Rayleigh-Ritz assumed mode method. The stiffness variation effect caused by the rigid body motion is considered in this modeling. The effects of the impulsive force position and the angular velocity on the transient responses of the beam are investigated through numerical studies.